Fish or Fish Oils?… the Omega 3 Controversy
>From cod liver to fatty acids, fish oil has long been considered healthy, but some say the current versions may do more harm than good
By Beth Daley, Globe Staff | April 20, 2004
It was a dreaded ritual for generations of children: A dose of cod- liver oil, an amber and vile-tasting cure meant to ward off everything from bone disease to ear infections.
Now, after decades of being relegated to Grandma’s medicine cabinet, fish oil is back in vogue. Fueled by health-conscious consumers looking for a quick boost of omega-3 fatty acids, US fish oil supplement sales have almost tripled since 1997 to more than $131 million, and are among the fastest growing supplements in the country, according to Nutrition Business Journal, a research and marketing company.
But the standard-setting United States Pharmacopeia, or USP, warned last month that fish oil pills may contain some of the same high levels of PCBs, arsenic and other toxins that accumulate in wild fish. Some scientists say lax regulations of all dietary supplements mean that the consumers can’t be sure the pills are pure.
"[Fish oil supplements] are not subject to oversight and USP is very concerned about that," said V. Srini Srinivasan, vice president of the United State Pharmacopeia’s Verification Program for dietary supplements. His nonprofit group is developing standards for toxins in fish oil that will take effect in about six months.
Equally worrisome, some nutrition experts say: Diners are using the pills as an excuse to give up nutritious fish meals, perhaps eating artery-clogging red meat instead.
The concerns come after years of hearing only good news about omega- 3s in fish oil. A flurry of studies has shown that the fatty acids found in fish are a sort of modern-day elixir, helping prevent heart disease and perhaps also easing depression and complications from cystic fibrosis, among a host of other ailments.
Fish oil was once an industrial product, used to waterproof boats, Illuminate lighthouses, make paint glide on easily and tan leather. The health benefits of fish oil — particularly oil derived from the livers of cod – were documented as far back as the 1750s. Back then, it was the benefits of vitamins A and D that were prized, not the fatty acids.
Humans are unable to manufacture enough of these fatty acids and must get them from cold-water fish, or a less-potent kind found in flaxseeds and dark, leafy, green vegetables. But many people don’t eat enough fish high in omega-3s to meet dietary guidelines and so take pills instead.
Most fish oil pills currently come from small bony fish such as menhaden, whiting or anchovy — not cod livers. They often come in one-a-day capsules, and while some smell rancid if broken open, most are coated and have no odor or taste. Still, some of the pills do have problems with fishy reflux and recommended doses can vary from supplement to supplement.
Producers of some of the more popular brands of fish oil say their pills do not have high levels of contaminants because their fish oil undergoes a process that removes most impurities. Some scientists say the fish used in fish oil pills are not long-lived enough to accumulate toxins. And Consumer Reports, a magazine that reviews product attributes and safety, recently tested several well-known brands and found that none contained dangerous levels of mercury, PCBs or dioxin.
In fact, some scientists expressed concern last week that the USP was too stringent in its warning, especially because the group mentioned mercury, which is normally found in the tissue of fish, not its oil, and because tested fish oil pills have not shown any dangerous levels of toxins.
"It was a little irresponsible," said David Schardt of the Center for
Science in the Public Interest, a nutrition advocacy group.
Fish oil supplement makers insist their product is safe. "All our fish oil supplements have been independently tested: There are no detectable levels" of toxins, said Crystal Wright, vice president of public relations for Leiner Health Products, which markets fish oil supplements under store brand names such as CVS. Her company’s fish pills were among those endorsed by Consumer Reports.
Still, some scientists say consumers should be careful about unbranded supplements, particularly those sold on the Internet and those without any evidence of independent testing. The USP also warns against supplements made from halibut, shark liver oils or cod liver, because they may contain excessive levels of vitamin A.
And in almost every situation, it’s better to eat fish than pop a pill to get the same benefit.
"I would recommend people consume fish, because of the omega-3 fatty acids, and if they are consuming fish, they are displacing fats from other parts of the diet," said Alice H. Lichtenstein, a professor of nutrition science and policy at Tufts University.
Others say omega-3s are so important that it’s OK to take pills if that’s the only realistic method of getting fish oil.
"Some people don’t like fish, and the pill may be the only way to get it," said Anthony Bimbo, a consultant to the seafood industry about fish oil who has written several papers on the subject.
Even some scientists who advocate eating fish, however, say pregnant and nursing mothers should temporarily look elsewhere for their omega-3s.
And there are other potentially safer ways of getting omega-3s, such as from algae where omega-3s originate, and that have none of the contaminants of wild fish. Algae oil pills can be hard to find, though, and are usually more expensive than fish oil.
Another option: Eating the eggs of chickens fed dried algae, according to Eric Decker, professor of food science at the University of Massachusetts at Amherst.
There is also a growing effort to give people their omega-3s in other food sources, by injecting fish oils into burgers or bread. Already some Texas schools are beginning to fortify students’ breakfast tamales and cheese sauces with tasteless menhaden oil.
"It would be great to include more fish products on the menu, but they are not as popular," said Margaret Lopez, an education specialist with the child nutrition program at Texas’s Region 1 Education Service Center. "This is one way to get students their omega-3s."
Note: There is a lot of confusion and controversy about fish oils. Dr. Gordon’s book "The Omega-3 Miracle" is the definitive guide on how to maximize your health and longevity with them. Find it on the New Book table at Barnes and Noble starting May 19th.